Page 17 - Manual of Equine Field Surgery

Wound Closure 13

depths of the wound. This systematic approach controlled by the inflammatory and debridement

helps to prevent contamination of deeper tissues phases of healing but prior to granulation tissue

with debris from more superficial layers as formation. Delayed primary closure is best used

debridement progresses and preserves viable for contaminated, contused, or swollen wounds

tissue. Staged debridement is a method of layered and for those involving a synovial structure. It is

debridement that minimizes tissue loss. In most particularly useful in distal limb wounds, where

equine distal limb wounds, where tissue is at a contamination is a frequent problem.

premium, staged debridement is used over a Delayed secondary closure is performed 1nore

number of days to avoid inadvertent removal of than 5 days after injury, once granulation tissue

viable tissue. Wl1e11 performing staged debride- has begun to form. As with delayed primary

ment, the two governing criteria are color and closure, delayed secondary closure is used after

attachment. White, tan, black, and green tissues, several days of therapeutic care for contaminated

as well as those that are poorly attached, should wounds with compromised blood supply. At

be debrided. Tissues that are pink to dark pur- the time of closure, the granulation tissue is

ple and well attached should be left in place. removed to allow apposition of skin edges. This

Non-surgical methods of wound debridement may result in significant dead space or oozing of

include chemical or enzymatic debridement, laser blood and serum. Drains may be necessary to

debridement, bandaging techniques, or biosur- minimize the accumulation of serum within the

gical therapy. These techniques are discussed wound.

elsewhere. 6 Second-intention healing consists of fibropla-

sia followed by wound contraction and epithelial-

ization. Indications for second-intention healing

WOUND CLOSURE include severe contamination or infection, con-

siderable skin loss, excessive skin tension that pre-

Priorities during wound closure are to limit in- eludes primary closure, and unavoidable motion

fection or contamination, minimize skin loss, and like that occurring in the pectoral and gluteal

exert the least amount of tension possible on the regions. Second-intention healing is best used for

suture line. Ideally, wounds are managed by wounds not over a joint surface, those with an

primary closure. Wounds most amenable to adequate vascular supply to the underlying soft

primary closure include those of the head and tissues, and those with sufficient mobile skin to

upper body, flap wounds with a good blood supply, allow wound contraction.

and recent minimally contaminated wounds of the

extremities. Wounds with considerable skin loss, or

severe contamination or infection, should not be SUTURE MATERIAL

closed initially. These may be closed later using

delayed primary or secondary closure techniques Suture material selection should be based on the

or allowed to heal by second intention, biologic and physical properties of the suture, the

Primary closure, leading to first-intention wound environment, and the tissue response to

healing, is performed after surgery or soon after the suture (Table 3-1). The characteristics of the

injury, Ideally, primary closure is performed ideal suture include good handling quality; good

during the golden period. The golden period knot security; adequate tensile strength; lack of

relates to the time required for multiplying bacte- allergenic, electrolytic, capillary, or carcinogenic

ria to reach an infective level, considered to be 106 properties; minimal tissue reaction; no adverse

organisms per gram of tissue. Theoretically, this effects on a wound in the presence of infection;

time period is 6 hours. 111 actuality, this may be easily sterilized; economical; and absorption soon

longer i11 clean wounds and considerably shorter after the suture has served its pt1rpose.

in severely contaminated wounds. Primary clo- The suture material with the best handling

sure is best used for fresh, minimally contam- characteristics is silk, which, with respect to

inated wounds with a good blood supply without handling, sets the standard by which all other

involvement of vital structures. suture materials are compared. Generally, the

Delayed primary closure is performed 3 to 5 days braided, multifilament synthetic sutures have

after iniurv when the threat of infection has been better handling characteristics than monofila-